I’m still recovering from my mail meltdown. I’ve migrated all of Mail.app’s local mail to a local IMAP server, with a Maildir in my home directory. I was using Courier-imap but I had lots of trouble with it. This morning I installed Dovecot, which works a lot better. I first tried to install bincimap, which is available from DarwinPorts, but it wouldn’t build with either GCC 3.3 or 4.0.
I tried several email apps, including Entourage, PowerMail, and Mulberry and found that they all suck worse than Mail.app. Thunderbird isn’t too bad, but I’d prefer better integration with OS X’s addressbook.